NpH-MD-Simulations of the Elastic Moduli of Cellulose II at Room Temperatue

1996 ◽  
Vol 2 (9) ◽  
pp. 278-285 ◽  
Author(s):  
John Blackwell ◽  
Johannes Ganster
Keyword(s):  
Elastic Moduli ◽  
Md Simulations ◽  
Cellulose Ii

Stability of Cellulose Structures Studied by MD Simulations. Could Mercerized Cellulose II Be Parallel?

1996 ◽  
Vol 29 (17) ◽  
pp. 5695-5699 ◽  
Author(s):  
L. M. J. Kroon-Batenburg ◽  
B. Bouma ◽  
J. Kroon
Keyword(s):  
Md Simulations ◽  
Cellulose Ii ◽  
Cellulose Structures

Structure, Mechanical Properties, and Dynamic Fracture in Nanophase Silicon Nitride via Parallel Molecular Dynamics

1996 ◽  
Vol 457 ◽  
Author(s):  
Kenji Tsuruta ◽  
Andrey Omeltchenko ◽  
Aiichiro Nakano ◽  
Rajiv K. Kalia ◽  
Priya Vashishta
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Silicon Nitride ◽  
Dynamic Fracture ◽  
Elastic Moduli ◽  
Md Simulations ◽  
Multiphase Model ◽  
Order Of Magnitude ◽  
Parallel Molecular Dynamics

ABSTRACTMillion-atom molecular-dynamics (MD) simulations are performed to study the structure, mechanical properties, and dynamic fracture in nanophase Si3N4. We find that intercluster regions are highly disordered: 50% of Si atoms in intercluster regions are three-fold coordinated. Elastic moduli of nanophase Si3N4 as a function of grain size and porosity are well described by a multiphase model for heterogeneous materials. The study of fracture in the nanophase Si3N4 reveals that the system can sustain an order-of-magnitude larger external load than crystalline Si3N4. This is due to branching and pinning of the crack front by nanoscale microstructures.

Elastic Properties of Cellulose by Molecular Dynamics Simulation

2013 ◽  
Vol 416-417 ◽  
pp. 1726-1730 ◽  
Author(s):  
Xiu Mei Zhang ◽  
Sheldon Q. Shi ◽  
Jun Cao
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Crystalline Cellulose ◽  
Internal Stresses ◽  
Molecular Models ◽  
Reactive Force

Molecular dynamics (MD) simulations were performed on molecular models of cellulose represented by two crystalline samples and amorphous samples. Simulated elastic properties and structures of each cellulose model were studied by MD simulations with the reactive force field and compared against experimental data for corresponding sample. The simulation boxes in stretch provide the materials elasticity. When there is a strain, the energy increases and internal stresses were built up within the supercell. The elastic moduli of amorphous and crystalline cellulose were comparable to the literature value. The calculated results had negligible difference with the experimentally measured parameters that indicated that the initial structures were stable using the ReaxFF.

Molecular Dynamics Simulations of Nanoindentation of Silicon Nitride

1998 ◽  
Vol 539 ◽  
Author(s):  
Phillip Walsh ◽  
Andrey Omeltchenko ◽  
Hideaki Kikuchi ◽  
Rajiv K. Kalia ◽  
Aiichiro Nakano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Silicon Nitride ◽  
Elastic Moduli ◽  
Local Stress ◽  
Md Simulations ◽  
Stress Distributions ◽  
Surface Adhesion ◽  
Amorphous Silicon Nitride ◽  
Dynamics Simulations

AbstractThis is a report of work in progress on 10 million atom Molecular Dynamics (MD) simulations of nanoindentation of crystalline and amorphous silicon nitride (Si3N4). Nanoindentation is used to determine mechanical properties of extremely thin films such as hardness and elastic moduli. We report load-displacement curves for several Si3N4 configurations using an idealized non-deformable indenter and analyze the local stress distributions in the vicinity of the indenter tip. Preliminary results for surface adhesion using Si3N4 for both tip and substrate are also reported.

Efficient Treatment of Fixed and Induced Dipolar Interactions

2000 ◽  
Vol 653 ◽  
Author(s):  
Celeste Sagui ◽  
Thoma Darden
Keyword(s):  
Molecular Dynamics ◽  
Md Simulations ◽  
Lagrangian Formalism ◽  
Dipolar Interactions ◽  
Time Step ◽  
Efficient Treatment ◽  
Particle Mesh Ewald ◽  
Fixed Charges ◽  
Self Consistency ◽  
Induced Dipoles

AbstractFixed and induced point dipoles have been implemented in the Ewald and Particle-Mesh Ewald (PME) formalisms. During molecular dynamics (MD) the induced dipoles can be propagated along with the atomic positions either by interation to self-consistency at each time step, or by a Car-Parrinello (CP) technique using an extended Lagrangian formalism. The use of PME for electrostatics of fixed charges and induced dipoles together with a CP treatment of dipole propagation in MD simulations leads to a cost overhead of only 33% above that of MD simulations using standard PME with fixed charges, allowing the study of polarizability in largemacromolecular systems.

Epitaxial Growth in Dislocation-Free Strained Alloy Films

2002 ◽  
Vol 715 ◽  
Author(s):  
Zhi-Feng Huang ◽  
Rashmi C. Desai
Keyword(s):  
Deposition Rate ◽  
Elastic Moduli ◽  
Composition Dependence ◽  
Critical Thickness ◽  
Lattice Misfit ◽  
Misfit Strain ◽  
Joint Stability ◽  
Alloy Films ◽  
The Stability ◽  
Stability Results

AbstractThe morphological and compositional instabilities in the heteroepitaxial strained alloy films have attracted intense interest from both experimentalists and theorists. To understand the mechanisms and properties for the generation of instabilities, we have developed a nonequilibrium, continuum model for the dislocation-free and coherent film systems. The early evolution processes of surface pro.les for both growing and postdeposition (non-growing) thin alloy films are studied through a linear stability analysis. We consider the coupling between top surface of the film and the underlying bulk, as well as the combination and interplay of different elastic effects. These e.ects are caused by filmsubstrate lattice misfit, composition dependence of film lattice constant (compositional stress), and composition dependence of both Young's and shear elastic moduli. The interplay of these factors as well as the growth temperature and deposition rate leads to rich and complicated stability results. For both the growing.lm and non-growing alloy free surface, we determine the stability conditions and diagrams for the system. These show the joint stability or instability for film morphology and compositional pro.les, as well as the asymmetry between tensile and compressive layers. The kinetic critical thickness for the onset of instability during.lm growth is also calculated, and its scaling behavior with respect to misfit strain and deposition rate determined. Our results have implications for real alloy growth systems such as SiGe and InGaAs, which agree with qualitative trends seen in recent experimental observations.

Buckling Behavior of Tire Breaker Structure

1983 ◽  
Vol 11 (1) ◽  
pp. 3-19
Author(s):  
T. Akasaka ◽  
S. Yamazaki ◽  
K. Asano
Keyword(s):  
Elastic Foundation ◽  
Elastic Moduli ◽  
Wave Length ◽  
Bending Moment ◽  
Experimental Results ◽  
Automobile Tire ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Steel Cord ◽  
Interlaminar Shear

Abstract The buckled wave length and the critical in-plane bending moment of laminated long composite strips of cord-reinforced rubber sheets on an elastic foundation is analyzed by Galerkin's method, with consideration of interlaminar shear deformation. An approximate formula for the wave length is given in terms of cord angle, elastic moduli of the constituent rubber and steel cord, and several structural dimensions. The calculated wave length for a 165SR13 automobile tire with steel breakers (belts) was very close to experimental results. An additional study was then conducted on the post-buckling behavior of a laminated biased composite beam on an elastic foundation. This beam is subjected to axial compression. The calculated relationship between the buckled wave rise and the compressive membrane force also agreed well with experimental results.

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